Mayor Bloomberg makes a proclamation as he joins the cast of "Gossip Girl" to celebrate the show's 100th episode. At right, Blake Lively and Penn Badgley look on.

AP

During the event, held at Silvercup Studios in Queens, where the show is filmed, Bloomberg declared January 26 to be "Gossip Girl Day." Here, he and Blake Lively share a laugh as Penn Badgley looks bored.

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Bloomberg shows off a "Gossip Girl"-themed "Made in NY" T-shirt.

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Blake Lively and Penn Badgley seem to be sharing a bit of gossip of their own.